Jack gave a step forward the better to survey the scene before them. As he did so his right foot struck something, and the next instant there was a sudden sharp jangling of a bell.

In a flash he realized what had happened. A wire connected with the bell had been stretched across the path,—Herrera’s dead line. His forward step had given the alarm, and might prove their undoing and cause the total failure of their plans. Captain Andrews’ arm shot out and dragged the boy back into a clump of brush. He made Jack lie down flat, doing so himself.

“The whole pack will be about our ears in a minute,” he whispered; but he did not reproach Jack, whose face was burning with humiliation.

Sure enough, almost simultaneously there came from the direction of the houses and sheds an excited clamor of voices. Lights flashed and figures could be seen rushing about. Presently they gathered in a knot, and some one appeared to be giving directions; then they scattered in a fan-shaped formation, and moved toward the woods in which the two adventurers lay concealed.

Jack’s heart beat like a trip hammer. Beside him he could hear Captain Andrews breathing heavily. Their discovery, within the next few minutes, appeared inevitable. Flashing their lanterns hither and thither the searching party, which they could now see was composed of negroes, from the Mosquito coast in all probability, advanced toward the jungle.

There were a dozen or more of them, headed by the big fellow whom they had noticed on sentry duty. Almost all of them carried the universal weapon of the negro in the tropics, long, glittering-bladed machetes. Some of them took to the path by which Captain Andrews and Jack had reached their present position. Others plunged into the jungle, cutting away the thick growth with their steel blades.

Their leader shouted something in Spanish. “He’s ordering them to search every inch of the jungle hereabouts,” interpreted Captain Andrews in a whisper. “The precious rascal! I’d like to have my hands on him.”

“It wouldn’t do much good,” was the mournful response; “the odds against us are too heavy for us to do much in case of our discovery.”

“Well, we’ve got the gas-guns, and from what I’ve already seen of them I reckon that they may prove mighty useful in a few minutes.”

As he spoke there came a crashing sound in the undergrowth a few feet from them. The next moment they saw the form of a giant black looming up directly in front of them. The fellow was grunting from his exertions in cutting his way through the underwood, and paused for an instant to catch his breath.

It was a fatal pause for him. Jack gently drew his gas-gun toward him and fired. The negro threw both his hands into the air and dropped with a loud “Oof!”

But the shot had been at such close range that the powerful gas impregnated the air that Captain Andrews and his young companion were breathing. The reek of it stung their nostrils.

“We’ve got to get out of here,” whispered Jack, “or we’ll be as dead to the world as that fellow is.”

Painfully they crept on their stomachs through the thick brush, moving as silently as cats. A single mistake in their movements, the crack of a branch snapped by carelessness might, as they both knew, prove fatal. But they managed to gain a small clearing under some big trees without mishap.

It was at this moment that Jack had a sudden inspiration.

“See here,” he said excitedly, under his breath, “those chaps have worked past us now, to judge by the sounds. They think that we have fled through the woods. What’s the matter with our doubling back on our tracks and marching right into the settlement?”

Captain Andrews, ungiven as he was to emotion, fairly gasped.

“By the beard of Neptune, boy!” he exclaimed, and then, in the same breath, “but it’s not as mad a plan as it sounds. In all likelihood, almost the entire force of guards from the plantation buildings are out after us, and we ought to be more than a match for half a dozen with the gas-guns.”

“Then we’ll do it?” throbbed Jack, with a catch of his breath.

“Yes. We came here to rescue those poor chaps, and, by the Polar Star, we’ll do it if it’s possible.”

Jack impulsively held out his hand. Captain Andrews clasped it warmly. The next moment they were stealthily creeping through the undergrowth, but advancing far more quickly than they had retreated a moment before.

When they once more gained the edge of the jungle. Jack perceived, to his intense satisfaction, that everything was quiet about the handful of buildings before them. So far as could be seen, there was no one about. Evidently then, his surmise had been correct. The majority, if not all of the residents, were abroad in search of the persons who had sounded the alarm bell.

“Which building do you think it likely they are in?” asked Jack, as they paused an instant before plunging from the protection of the woods.

“The one that has that lantern hanging on it,

“I imagine,” was the response from the veteran seaman, “we’ll try that first, anyway. Are you ready?”

Jack nodded. He did not speak, however. It was not a time for mere words. The next moment they had passed from the dark shadows of the jungle into the open space about the plantation buildings. Each clasped his gas-gun ready for instant use. But nobody appeared to bar their progress.

When they gained the structure from which the lamp was hanging, they found that it was a tall building of wood, and seemingly three stories in height.

It was used, though they did not know this at the time, as a drying house for the hemp after it had been through the crushing and separating processes. The door was secured on the outside by a weighty bar of wood. Captain Andrews lifted this out of its sockets, and in a jiffy had flung the door open. Inside was pitchy darkness, so black that it could almost be felt.

Jack had brought along his electric pocket lamp. He drew it out and switched on the current. The rays revealed a large, bare chamber, empty, except for a pile of dry hemp in one corner, and in another a few bales of the product stacked ready for shipment.

“Nothing here,” said Captain Andrews briefly.

“No; but see, there’s a flight of steps in that corner. Let’s go higher and find out what’s on the floor above.”

“It may be wasting precious time, lad.”

“On the other hand, this was the building that was guarded by the sentry. It’s fair to assume, then, that it is in this structure that our friends are confined.”

Captain Andrews had nothing to reply to this logic, and followed Jack up the steps.

At the summit of the rickety staircase was another door, secured, as had been the one below, by a stout bar of wood. Jack tackled this and wrenched it free. As he did so a voice that thrilled him in every fiber came from within the portal.

“Who is it?”

“Dad! It’s me—Jack—I’ve come to save you!” blurted out Jack, tears of sheer gladness springing to his eyes. He flung the door open.

The next instant Jack was clasped in his father’s arms, while about him and Captain Andrews, pressed the other captives, all well and unharmed and half wild with delight as they greeted the lad whose pluck had conquered Herrera’s “deadline.”